A naked eye 3D display device includes a display panel and a liquid crystal grating. The liquid crystal grating for example is provided in front of the display panel, so that an image displayed by the naked eye 3D display device shows a 3D effect.
As shown in FIG. 1, the liquid crystal grating 1′ comprises a first substrate 2′, a liquid crystal layer 3′ and a second substrate 4′. Wide strip-shaped transparent electrodes 5′ are provided on the first substrate 2′ at equal intervals, and a narrow strip-shaped transparent electrode 6′ is provided between adjacent wide strip-shaped transparent electrodes 5′. A plate-shaped transparent electrode 7′ is provided on the second substrate 4′. A voltage of the narrow strip-shaped transparent electrode 6′ is same as a voltage of the plate-shaped transparent electrode 7′. In the case that there is an electric field between the wide strip-shaped transparent electrodes 5′ and the plate-shaped transparent electrode 7′, liquid crystal molecules in the liquid crystal layer 3′ corresponding to positions of the wide strip-shaped transparent electrodes 5′ are deflected. That is, in this case, the liquid crystal molecules in the liquid crystal layer 3′ corresponding to the positions of the wide strip-shaped transparent electrodes 5′ are deflected so that long axes thereof are perpendicular to the second substrate 4′ and light cannot transmit through the liquid crystal grating 1′, thereby forming light-shielding stripes. Since the voltage of the narrow strip-shaped transparent electrode 6′ between the adjacent wide strip-shaped transparent electrodes 5′ is the same as that of the plate-shaped transparent electrode 7′, the liquid crystal molecules in the liquid crystal layer 3′ corresponding to a gap between the adjacent wide strip-shaped transparent electrodes 5′ are not deflected, so that light can transmit through the liquid crystal grating 1′, thereby forming light-transmitting stripes.
As shown in FIG. 2, the liquid crystal grating 1′ is in front of a display panel 8′, and light-transmitting stripes 9′ and light-shielding stripes 10′ are alternately provided on the liquid crystal grating 1′, so that a left eye 11′ only sees a left-eye image and a right eye 12′ only sees a right-eye image, thereby making the displayed image show the 3D effect.
Inventor of the present disclosure found that, as shown in FIG. 3, there is a certain included angle between an arrangement direction of the liquid crystal molecules in the liquid crystal layer 3′ close to the first substrate 2′ and the first substrate 2′. Therefore, there is a relatively large included angle between a direction of the electric field (indicated by dotted lines) between an edge 13′ of the wide strip-shaped transparent electrode 5′ and the plate-shaped transparent electrode 7′ and an arrangement direction of the liquid crystal molecules provided outside the edge 13′, and deflection states of the liquid crystal molecules provided outside the edge 13′ may be affected by the electric field, so that the liquid crystal molecules provided outside the edge 13′ deviate from their desired arrangement direction, resulting in a low light transmittance in the region of the liquid crystal molecules provided outside the edge 13′, which is significantly lower than light transmittances of both sides of this region. In this case, a black stripe appears in a region indicated by the dotted box, so that the display device has a poor display effect.